How did the CIA “mislead” the White House and Congress about the effectiveness of torture in their interrogation program?
Well, this presupposes that the White House and Congress were actually misled; which is not really plausible.
The ineffectiveness of torture has been extensively researched and proved, and the US military, the CIA, and the State Department have known that for at least the last 40 years. Even the Nazis knew that torture does not produce reliable information.
In Islam, we have known that torture does not produce sound intelligence at least since the waterboys of Quraysh changed their answer when they were beaten before the battle of Badr, telling the Sahabah what they wanted to hear, just to prevent further punishment.
All modern research on the subject upholds the understanding of Rasulullah that prisoners will lie to accommodate their torturers, and that there are better methods for extracting information from them.
But the reality, of course, is that the program had nothing whatsoever to do with gathering intelligence, and everything to do with instilling fear and hatred.
This is why torture was used by the CIA in Latin America in the 1980s, not to gather information from US enemies, but to deliver messages to them.
Intelligence agencies communicate with the enemies they have not captured by means of the enemies they have captured; inflicting physical torture on a detainee to inflict psychological torment on the rebels at large, to both terrify and provoke them.
Either the prisoner will be released to spread the news of what he endured, or else, his corpse will be released to tell its own grisly tale.
The use of brutality, again, their own experts tell them, succeeds only in radicalization. This was the goal, and it was achieved by the means they knew very well would work.